Geological dating isotope

Because the lead isotopes are created by decay of different transuranic elements, the ratios of the four lead isotopes to one another can be very useful in tracking the source of melts in igneous rocks, the source of sediments and even the origin of people via isotopic fingerprinting of their teeth, skin and bones.

The ratio of non-radiogenic osmium to radiogenic osmium throughout time varies.

When an organism dies, the amount of C) in the material.

As a result, measuring the proportion of radiocarbon remaining in the sample compared to amount it would have had when alive provides an objective method of determining the time ranges within which the organism died.

Helium-3 is created by cosmic ray bombardment, and by lithium spallation reactions which generally occur in the crust.